Background

Application fonts are the fonts used within an application, where a wide variety of text designs, styles, weights and point sizes are useful. These variations are used for emphasis, cross-references, section headers, and so forth. There are thousands of fonts available in the market for use in applications, and different XCDE systems will have different fonts. The standard names attempt to provide the minimum variety in generic designs, styles and sizes that an application might want to use as defaults. (The XCDE Standard Interface Font Names, described in DtStdInterfaceFontNames(5), provide a similar mechanism for the elements of the XCDE desktop itself.)

Common application font names prevent applications from needing different app-defaults files on each XCDE system. The Standard Application Font Names allow applications to use a single app-defaults file across all XCDE systems. In addition, any X server or X terminal vendor may ensure that XCDE applications can run on their X server by mapping these standard application names to fonts of the corresponding style on their individual X systems.

Rationale

Two of the most common design variations in fonts used to display text are the presence or absence of serifs and the choice between proportional or regularly spaced (mono-spaced) characters. Combining these two design variations yields four ``generic'' font designs, or families:

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serif proportionally-spaced

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sans serif proportionally-spaced

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serif mono-spaced

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sans serif mono-spaced

Common examples of these four designs are:

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Times Roman

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Helvetica

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Courier

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Lucida Sans Typewriter

Each of these designs typically come, for text fonts, in four styles (combinations of weight and slant):

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plain

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bold

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italic

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bold-italic

The four styles of each of the four design variations yield 16 generic font variations. These 16 generic fonts are among the most commonly used in general desktop computing. For example, taking the first three real examples above (Times Roman, Helvetica, Courier), these 12 fonts, along with the Symbol font, constitute the so-called ``Adobe 13'' that is a de facto minimum set of fonts in the PostScript community in the desktop computer marketplace.

In some cases, applications do not care about the exact font family or name to be used, but do need to use a mono-spaced font, a sans serif font or a serif font. This XCDE mechanism allows such applications to be freed from the need to be concerned about the exact font names that may or may not be present on a particular XCDE system.

The Standard Names for the Latin-1 Character Set

The 13 standard application font names are provided on all XCDE systems only for the ISO 8859 (Latin-1) character set. These represent 12 generic design and style variations (serif and sans serif proportionally-spaced, and a mono-spaced font that is either serif or sans serif), as well as a symbol font. These standard names are provided in addition to the ``real'' names of the fonts that the standard names are mapped to for a particular XCDE system. An additional four standard font names, to allow both serif and sans serif designs in a mono-spaced font, may also be provided by a XCDE system.

XLFD Field Values for the Standard Application Font Names

The standard names are available using the X Window System XLFD font naming scheme. There are three aspects to the standard names:

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The underlying font on each system, or X server platform, to which a standard name is mapped, typically will be different on each system.

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The standard name itself, a full XLFD name mapped to the underlying font, may be different on each system in some of the XLFD fields. However, most of the fields are the same from system to system, allowing the patterns (described next) to be the same.

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The font resource pattern containing the * wildcards, used in app-defaults files, which will match the full XLFD name of the standard name, is the same across all systems, for a given use in an app-defaults file.

Each XCDE or X server vendor implementing this specification must provide full XLFD names for the standard names, mapped to system-dependent underlying fonts, so that the XLFD patterns used in XCDE application app-defaults files will always match one of the full XLFD names provided.

The Standard Application Font Names are identified by the presence of the following XLFD field name values:

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FOUNDRY is dt

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FAMILY_NAME is application

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WEIGHT_NAME is medium or bold

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SLANT is r or i

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SETWIDTH is normal

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ADD_STYLE is sans for sans serif, serif for serif

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SPACING is p or m

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CHARSET_REGISTRY is iso8859

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CHARSET_ENCODING is 1

Although sans and serif are not required by the XLFD font convention, they are always part of the standard XCDE font names.

Point Sizes

The complete set of point sizes available for each of the standard application font names is determined by the set of fonts included in a system, whether bitmapped only or both bitmapped and scalable outline. The minimum set of sizes required and available on all XCDE systems corresponds to the standard sizes of bitmapped fonts that make up the default mapping for X11R5: 8, 10, 12, 14, 18 and 24.

For example, the entire set of six sizes of the plain monospaced font, on any XCDE system, is represented by:

-dt-application-medium-r-normal-*-*-80-*-*-m-*-iso8859-1
-dt-application-medium-r-normal-*-*-100-*-*-m-*-iso8859-1
-dt-application-medium-r-normal-*-*-120-*-*-m-*-iso8859-1
-dt-application-medium-r-normal-*-*-140-*-*-m-*-iso8859-1
-dt-application-medium-r-normal-*-*-180-*-*-m-*-iso8859-1
-dt-application-medium-r-normal-*-*-240-*-*-m-*-iso8859-1

These patterns will match the corresponding standard font name on any XCDE system, even though the PIXEL_SIZE and AVERAGE_WIDTH numeric fields may be different on various systems, and the matched fonts may be either serif or sans serif, depending on the implementation of the set of standard names. The RESOLUTION fields in the XLFD names of the underlying fonts, when those fonts are bitmapped fonts, must match the resolution of the monitor on which the fonts are displayed for the point sizes to be accurate. To provide expected point size behavior for applications, systems should ensure that the RESOLUTION_X and RESOLUTION_Y fields of the underlying fonts vary no more than 20% from the real monitor resolution of the displays on which the fonts will be used.

Applications requesting point sizes different from the six in the minimum set may obtain either ``scaled bitmapped'' fonts of the requested design, or scaled outline versions of the requested design. This behavior requires that the X server in question support the scaling of fonts and that the standard names are mapped to underlying fonts that can be scaled using this support.

Example XLFD Patterns for the Standard Names

Using the specified field values for these standard names, subsets of the standard names can be represented with various XLFD patterns. The XLFD pattern

-dt-application-*

logically matches the full set of XCDE Standard Application Font Names. (Note that no specific X server behavior is implied). The pattern

-dt-application-bold-*-*-*-*-*-*-*-p-*-*-*-

matches the bold, proportionally-spaced XCDE fonts, both serif and sans serif. And the pattern

-dt-application-*-*-*-*-*-*-*-*-m-*-*-*-

matches the monospaced fonts (including both serif and sans serif).

The full set of XCDE Standard Application Font Names can be represented with the following patterns:

-dt-application-bold-i-normal-serif-*-*-*-*-p-*-iso8859-1
-dt-application-bold-r-normal-serif-*-*-*-*-p-*-iso8859-1
-dt-application-medium-i-normal-serif-*-*-*-*-p-*-iso8859-1
-dt-application-medium-r-normal-serif-*-*-*-*-p-*-iso8859-1
-dt-application-bold-i-normal-sans-*-*-*-*-p-*-iso8859-1
-dt-application-bold-r-normal-sans-*-*-*-*-p-*-iso8859-1
-dt-application-medium-i-normal-sans-*-*-*-*-p-*-iso8859-1
-dt-application-medium-r-normal-sans-*-*-*-*-p-*-iso8859-1
-dt-application-bold-i-normal-*-*-*-*-*-m-*-iso8859-1
-dt-application-bold-r-normal-*-*-*-*-*-m-*-iso8859-1
-dt-application-medium-i-normal-*-*-*-*-*-m-*-iso8859-1
-dt-application-medium-r-normal-*-*-*-*-*-m-*-iso8859-1
-dt-application-medium-r-normal-*-*-*-*-*-p-*-dtsymbol-1

Each of these 13 standard names comes in at least six point sizes.

Implementation of Font Names

Each XCDE system vendor and X server vendor provides mappings of their own fonts to XLFD names meeting this standard, so that XCDE applications will work on their system. The actual XLFD names will vary from system to system, just as the fonts they are mapped to, since they contain some of the same values as the XLFD name of the underlying font. What does not vary is the behavior: the common patterns in which only specified fields are used will match each system's standard names. This is guaranteed by the field specifications given earlier.

The following requirements are placed on each XCDE or X server vendor's implementation of the Standard Application Font Names:

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The names must be fully specified XLFD names, without wild cards.

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The WEIGHT_NAME, SLANT, SETWIDTH_NAME, SPACING, CHARSET_REGISTRY and CHARSET_ENCODING fields must contain valid values as defined previously and must match those in the underlying font.

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The ADD_STYLE_NAME field must contain either the serif or sans designation, whichever matches the underlying font.

Default XCDE Mappings for Latin-1 Locales

The default mapping of these standard application font names for the ISO 8859 locales is to the following standard X11R5 bitmapped fonts (the six minimum sizes are not shown explicitly in these patterns):

-adobe-times-bold-i-normal--*-*-*-*-p-*-iso8859-1
-adobe-times-bold-r-normal--*-*-*-*-p-*-iso8859-1
-adobe-times-medium-i-normal--*-*-*-*-p-*-iso8859-1
-adobe-times-medium-r-normal--*-*-*-*-p-*-iso8859-1
-adobe-helvetica-bold-o-normal--*-*-*-*-p-*-iso8859-1
-adobe-helvetica-bold-r-normal--*-*-*-*-p-*-iso8859-1
-adobe-helvetica-medium-o-normal--*-*-*-*-p-*-iso8859-1
-adobe-helvetica-medium-r-normal--*-*-*-*-p-*-iso8859-1
-adobe-courier-bold-o-normal--*-*-*-*-m-*-iso8859-1
-adobe-courier-bold-r-normal--*-*-*-*-m-*-iso8859-1
-adobe-courier-medium-o-normal--*-*-*-*-m-*-iso8859-1
-adobe-courier-medium-r-normal--*-*-*-*-m-*-iso8859-1
-adobe-symbol-medium-r-normal--*-*-*-*-p-*-adobe-fontspecific

A system may provide a different mapping of these standard names as long as all 13 names map to fonts of the appropriate design and style and the required six point sizes are available. The system documentation must document the system-specific default mapping for the standard names.

Font Names in app-defaults Files

An application can use a single app-defaults file to specify font resources and use it across all XCDE systems. Since most of the fields ( FOUNDRY, FAMILY_NAME, WEIGHT_NAME, SLANT, SETWIDTH_NAME, ADD_STYLE_NAME, POINT_SIZE, SPACING, CHARSET_REGISTRY and CHARSET_ENCODING) of the standard names are the same across different systems, these values can be used in the resource specification in the app-defaults file. However, other fields ( PIXEL_SIZE, RESOLUTION_X, RESOLUTION_Y and AVERAGE_WIDTH) may vary across systems, and so must be wild-carded in the resource specification. For example:

appOne*headFont: -dt-application-bold-r-normal-sans-*-140-*-*-p-*-iso8859-1
appOne*linkFont: -dt-application-bold-i-normal-sans-*-100-*-*-p-*-iso8859-1

might be used to specify some of AppOne's default font resource needs.

Other Character Sets in the Common Locales

The standard application font names defined above can be used for locales other than the ISO 8859 character set with the following exceptions and differences. For the following locales, CDE guarantees that systems provide fonts with the following XLFD attribute values, and that they be accessible using these names. For full information on how vendors ship the fonts, and make such names usable with the appropriate font base name lists required for correct CDE support for internationalization, see the guidelines in the CDE Internationalization Programming Guide document.

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Locales using ISO 8859-2, -3, -4, -5 (Cyrillic), -6 (Arabic), -7 (Greek), -8 (Hebrew):

The same values for FOUNDRY, FAMILY_NAME, WEIGHT_NAME, SLANT, SET_WIDTH, ADD_STYLE and SPACING as are used in this definition for the ISO 8859 locale.

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Japanese locales:

Two values for the FAMILY_NAME attribute (Gothic and Mincho) and two values for the WEIGHT_NAME attribute (medium and bold) as well as SLANT (r), ADD_STYLE (*) and SPACING (m).

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Chinese (Taiwan) locales:

Two values for the FAMILY_NAME attribute (Sung and Kai) and two values for the WEIGHT_NAME attribute (medium and bold) as well as SLANT (r), ADD_STYLE (*) and SPACING (m).

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Chinese (PRC) locales:

Two values for the FAMILY_NAME attribute (Song and Kai) and two values for the WEIGHT_NAME attribute (medium and bold) as well as SLANT (r), ADD_STYLE (*) and SPACING (m).

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Korean locales:

Two values for the FAMILY_NAME attribute (Totum and Pathang) and two values for the WEIGHT_NAME attribute (medium and bold) as well as SLANT (r), ADD_STYLE (*) and SPACING (m). Note that these names are unofficial, tentative romanizations of the two common font families in use in Korea; Totum corresponds to fonts typically shipped as Gothic, Kodig or Dotum and Pathang corresponds to fonts typically shipped as Myungjo or Myeongjo. The official roman names for these fonts are under review and may be changed in the future by the Korean government, and thus may change for CDE.

In addition, to facilitate app-defaults files that work under a variety of locales, CDE systems must provide an additional set of Standard Application Font Names where the FAMILY_NAME is application. These font names are identified by the presence of the following XLFD field values:

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FOUNDRY is dt

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FAMILY_NAME is application

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WEIGHT_NAME is medium or bold

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SLANT is as appropriate (see above)

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SET_WIDTH is normal

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ADD_STYLE is *

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SPACING is as appropriate (see above)

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CHARSET_REGISTRY is as appropriate

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CHARSET_ENCODING is as appropriate

This set of names is mapped to an underlying font representing one of the FAMILY_NAMES as listed above.

For example, the XLFD names

-dt-mincho-medium-r-normal--*-*-*-*-m-*-jisx0208.1983-0
-dt-application-medium-r-normal--*-*-*-*-m-*-jisx0208.1983-0

may both be mapped to

-ibm_aix-mincho-medium-r-normal--*-*-*-*-m-*-jisx0208.1983-0

This scheme allows application writers to create a XmFontList in a resource file as follows, without regard for a particular locale:

*FontList:-dt-application-medium-r-normal-*-0-14-75-75-m-0-*-*:

and be assured that the font will be reasonable. Notice that specifying fonts this way not only disregards the selection of the Asian FAMILY_NAME, but also the Latin serif or sans ADD_STYLE field. The font selected will be the default.